The killers were so unconcerned about being identified they did not even bother to wear masks. This was Sicily after all.

They opened fire as their victims were drinking coffee and reading the papers in a bar in the small town of Vittoria.

Sicily killing: Witnesses observe the code of silence

The gunmen fired more than 40 rounds. But the bar manager and a garage attendant present during the attack could provide few details for the police. They said they had been too busy taking cover to see anything.

Mafia killings in Sicily do not tend to produce a queue of witnesses. The local priest has called on his parishioners to break the code of silence or omerta.

"Tell me what you know," he said. "If you are afraid to speak out, I'll take the risk." But there has been no rush to respond to his invitation.

Investigators believe the killings were part of a battle between rival Mafia clans for control of the drugs trade. Two of the victims were innocent bystanders - in the wrong place at the wrong time.

Campaign against the Mafia

High profile attacks like this have been a rarity in Sicily in recent years. Mafia killings have been far fewer in number and more low key.

Organised crime has been busy taking care of business. And the police have been making progress against the Cosa Nostra - many bosses have been put behind bars. But those still on the streets are vying for supremacy.

The killings, and the silence in their wake, prove that the Mafia is still an intrinsic part of life in Sicily.

There, organised crime is not discussed in terms of them and us. The Cosa Nostra, whether tolerated or despised, is not seen as something separate from the rest of society.

On my first visit to the island two years ago I was confronted by an angry taxi driver who complained that the state's anti-Mafia drive was stifling the local economy.

Massimo Dalema: Cannot see an end to organised crime

That drive has produced results. So much so the tourist board has put up posters announcing that the biggest problem there now is traffic. It is a claim that many find blackly amusing.

Things may be better than they used to be, but even Italy's Prime Minister Massimo Dalema admits that the fight against organised crime will probably never end.

Mafia bosses are no longer engaged in all out war against the state - as they were in the early 1990s - but they are still prepared to silence those who dare to oppose them.

Last October the Mafia carried out its first political assassination in six years. A trade union official in Sicily was shot dead on the steps of his home in front of his son. Domenico Jeraci was running for mayor on an anti-Mafia ticket.

For the Cosa Nostra death is simply a way of doing business.

New leaders replace old guard

Some time ago I met one of Sicily's most notorious former Mafia bosses. These days Diego Iayetti has retired from crime, and lives under 24-hour police guard in Italy's witness protection programme.

When I asked him how many lives he had taken there was a pause. Expecting to hear denials or justifications I was shocked by his expansive response.

"Well, let me see," he said calmly. "Some I killed myself, others I gave the orders for. Some I started and others finished. In some cases I did the job with the help of my brothers. Really it was so many I can't quite remember."

A former Mafia boss is escorted to his trial

For the record Diego Iayetti was accused of 27 murders.

A young Sicilian journalist, a colleague and friend, was present during this rare interview. When Iayetti was taken away he was close to tears. "I grew up with this," he said. "Men like him have killed my people and ruined my home."

For every Mafia boss who is captured or finds a safe haven in the witness protection programme, there is another one to take his place.

The Cosa Nostra is now believed to be headed by a man police have nicknamed The Tractor, because they say, he mows people down.

Bernardo Provenzano, memorably described as "shooting like a God, but having the brains of a chicken", has so far eluded capture for almost 40 years.